X0306 4 2020-12-03 0001267565 COLLEGIUM PHARMACEUTICAL, INC COLL 0001640701 Fleming Alison B C/O COLLEGIUM PHARMACEUTICAL, INC. 100 TECHNOLOGY CENTER DRIVE STOUGHTON MA 02072 0 1 0 0 Chief Technology Officer Common Stock 2020-12-03 4 S 0 5967 19.24 D 111419 D The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on November 19, 2020. The price reported in column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $19.03 to $19.37, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnote (2) to this Form 4. /s/ Paul Brannelly as Attorney-In-Fact For Alison B. Fleming 2020-12-07